ENERGY-SAVING TIPS

While you’re thinking about insulation and ventilation, you should also pay attention to a few other details that relate to energy conservation. Taken together, these small improve­ments can make a big difference in how well your house works.

■ Locate the water heater near the kitchen and bathroom.

This avoids long runs of pipe that increase plumbing costs and dissipate heat between the water heater and the faucets or showerheads.

■ In cold climates, keep water-supply lines out of exterior walls.

■ Use an insulated wrap for the water heater. New water heaters typically come with built-in insulation, which helps keep your energy costs low. Another money saver is water heaters that come with timers. This allows you to activate the unit during specific times of day when heated water

is needed.

■ Insulate all hot-water lines, and insulate cold-water lines in a crawl space. Both foam and fiberglass-wrap pipe — insulation kits are available at building-supply outlets and home centers.

■ Install low-flow showerheads. A showerhead with a built-in shutoff valve provides even more savings, allowing you to shut off the water while soaping up.

■ Consider using a small solar panel to preheat your water. The sun’s energy is free. With a solar panel, you can reduce the energy used by your hot-water heater.

Habitat for Humanity has developed many guides to help homebuilders and homeowners save energy and money. They are available online and from HFH International (see Resources on p. 279).Take advantage of these resources and increase your understanding of how to build durable, energy-efficient houses with good indoor-air quality.

Avoid single-speed fans. You’ll appreciate having a vent fan that can operate at more than one speed. Multiple-speed and variable-speed models cost a little more, but they enable you to use a lower, quieter speed during extended operation.

inspectors) have some catch-up work to do when it comes to understanding house ventila­tion. You’re better off finding a knowledgeable and reliable HVAC (heating, ventilation, and air-conditioning) contractor with up-to-date knowledge of home ventilation requirements. That said, proper ventilation for small, afford­able houses isn’t all that difficult to obtain.

Source ventilation is the key to reducing moisture and odors

You can start by installing adequate spot, or source, ventilation wherever moisture or odors are created. Venting moist air directly to the outside prevents it from escaping through the walls or ceilings, where it can cause damage.

At a minimum, showers and stoves should have exhaust fans that are controlled by simple on-off switches or wired to come on automati­cally when a bathroom light is turned on or the stove is being used. For a stove installation, mechanical ventilation is usually provided by a vent hood equipped with a fan. In a bathroom, a variety of ceiling-mounted fans are available, including models with built-in lights.

Exhaust fans in moisture-producing areas should always be vented directly outdoors.

That means out through a wall or up through the roof and not into an eave soffit or a crawl space. When we moved into our home in Oregon, I discovered that the clothes dryer was vented into the crawl space. Some pretty creepy looking stuff was growing down there in the dark. Even worse is venting moist kitchen or bathroom air into the attic.

Try to keep vent runs short—less than 10 ft., if possible. Avoid running vents through the attic, if possible; install them in interior soffits and dropped ceilings instead. If you can’t avoid running a vent through the attic, then make sure it is well insulated. This is cru­cial in cold climates, where heat inside the attic can cause ice damming along the eaves. This is serious business, so pay attention to the details.

Good indoor-air quality requires air exchange

We all need fresh air to stay healthy, and in a tightly built house, some form of mechani­cal air exchange is essential. You can provide air exchange fairly inexpensively by using a bathroom exhaust fan controlled by an auto­matic timer. Look for a fan that moves air at 80 CFM (cubic feet per minute) to 120 CFM.

Set the timer to run the fan about two-thirds of the time that people are generally home (it doesn’t make much sense to exchange air when no one’s home). The fan we have in our home is centrally located in a hallway, but check with your HVAC contractor to locate yours. Beware of bargain-priced fans. Those models are almost always noisier than other vent fans. An expe­rienced HVAC contractor can advise you on which models run quietly and reliably.

Whenever fans are blowing indoor air out­side the house, fresh air must come in to replace it. This ensures a healthy supply of fresh air and prevents negative air pressure from draw­ing exhaust gasses from the fireplace or furnace flues, which is a serious safety hazard. The simplest way to provide replacement air when exhaust fans are running is to open a window or two. It’s not necessary for the window to be fully open; just a crack will usually do. If it’s cold outside, open a window in a utility room, unused bedroom, or somewhere away from the main living area.

If you’re building a house where the winters are long and very cold (in Maine or Minnesota, for example), it may be necessary to have an HVAC contractor install a heat recovery ven­tilator (HRV) or an air-handling unit to bring replacement air into the house at a more com­fortable temperature. Those devices typically work by blowing warm indoor air outdoors while pulling an equal volume of outside air in­doors. Because only a thin membrane separates the passing airstreams, some of the interior’s warmth is transferred to the fresh incoming air.